There had been the familiar murmurings of discontent from a minority of those in the stands when Fernando Torres' name was announced prior to kick-off here, though by the end Chelsea were delighted to have him.

The Spaniard has enjoyed so few outings like this since his British record move from Merseyside but, with his face masked as if he had come incognito, Rubin Kazan found him unrecognisable from the player who has spluttered so often over the last two years. His team have a two-goal lead to take to Moscow, and Torres has a brace to savour.

How he must crave confronting opponents this defensively frail every week. The 29-year-old terrorised a brittle back-line here, all slippery movement across the turf to unsettle the full-backs and even upper body strength as he turned centre-halves. His scruffy, predatory opening goal had raised his confidence, his touch more assured in the exchanges that ensued. He purred at times, sprinting at a hapless Vitali Kaleshin, as he revelled in Rubin's shortcomings. The headed reward midway through the second period from Juan Mata's typically delicious delivery has given Chelsea breathing space.

That second, thumped beyond an exposed Sergei Ryzhikov, had actually been Torres' 18th goal in all competitions, a tally that, given the toils he has endured at times, reflects the cluttered nature of this team's schedule. This was the forward's 52nd club appearance of the campaign – Chelsea have now managed 56 – which, given the quality of the supply-line, was always likely to yield a respectable goals return. Yet to witness him collect on his instep and tease back-pedalling opponents, even beleaguered Russian journeymen like Kaleshin, was to be reminded of what he can achieve when his juices are flowing.

One visiting reporter jokingly asked Rafael Benítez if Torres should stick with the mask until the end of the season. "He may have to, anyway," came the response. The broken nose had been sustained against Steaua Bucharest in the previous round, a blow to the head that appears to have juddered the old Torres awake. He had excelled that night too, albeit also missing a penalty en route, but this was another step up. He had already out-muscled Roman Sharonov on the turn once when he stretched to reach David Luiz's wonderfully arced pass. Sharonov and Kaleshin were powerless to intercept and, even if the first touch was not perfect, the centre-back's tumble betrayed his desperation as Torres reacted quickest to prod the loose ball beyond Ryzhikov.

It was a mess of a goal for Rubin to surrender, particularly given they are a side prone to defensive stinginess. Kurban Berdyev's team have conceded only 19 in 22 domestic league games but they offered only panicked resistance when probed by Torres' darts and Mata's clever promptings. Chelsea swarmed all over them, sensing further gains. Victor Moses might have provided one only for Ryzhikov, initially confused by the lack of pace on a downward header, to push away the Nigerian's attempt unconvincingly. Yet Rubin never recovered their poise as Chelsea recycled the ball down their left and, after a series of ricochets and fluffed clearances, Moses dispatched a glorious half-volley into the top corner from just inside the penalty area with Ryzhikov helpless.

Chelsea should have had the tie settled there and then, their dominance so evident. "We were cruising," said John Terry, though that was perhaps their undoing. Concentration wavered briefly, the hosts retreating as they sensed the break. Cristian Ansaldi cut inside as half-time approached and spat a shot at goal which struck the home side's captain on his fluorescent armband, with the Italian official awarding a penalty. The attempt had been goalbound, even if Terry's arm had been by his side as the ball careered into his biceps. "When someone has a shot 10 yards away it's difficult to react," bemoaned the centre-back. "It's different when your arm's up but mine was by my side." Bebras Natcho cared little and dispatched the penalty beyond Petr Cech and, with José Rondon summoned from the bench for the second period to add bite and brawn to the visitors' front-line, the tie briefly hung in the balance.

Yet Rubin's vulnerability remained throughout. Ryzhikov was forced to save from Mata before the Spaniard's cross between Cesar Navas and Ansaldi was too tempting for Torres to pass up. A two-goal lead feels more comfortable, even with Chelsea fragile travellers at times. They will be thankful next week's return will be in Moscow's Luzhniki stadium – for all the nightmarish memories of penalty shoot-outs and 2008 – rather than at Rubin's own Tsentrainiy arena around 500 miles further east, where the locals are unbeaten in 18 Uefa games. Wherever they play, it is likely to be bitterly cold, though it is the Russians' riposte on the pitch rather than the climate that will prompt the main concern.

Should Rondon find his form after the lull of the international window, and Natcho his range from midfield, then it will still be an awkward occasion in the capital. "But we have confidence we can do it there," added Benítez. "They'll attack us and they have players of quality, but we can get through." The cluttered fixture schedule shows no sign of easing though Benítez, and a revitalised Torres, will not be complaining just yet.